JP2016012133A - Polarization film, antireflection film, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarization film, an antireflection film, and a display device.SOLUTION: A polarization film 50 includes: a polarization layer 70 including a polymer resin and at least one dichroic dye that has a maximum absorption wavelength (λ) at 380 nm to 780 nm; and protective layers 80a, 80b positioned on at least one face of the polarization layer 70 and having a crosslinking structure. An antireflection film 55 comprises the polarization film 50, and a phase difference film 95 across an adhesion layer 90 positioned on one face of the polarization film 50, and has an effect of preventing reflection of external light.

Description

  The present invention relates to a polarizing film, an antireflection film, and a display device.

  Display devices such as a liquid crystal display (LCD) and an organic light emitting diode device (OLED device) have a polarizing plate attached to the outside of the display panel. . The polarizing plate allows only light oscillating in a specific direction to pass therethrough and other light is absorbed or reflected, whereby the direction of light incident on the display plate or light emitted from the display plate can be controlled.

  The polarizing plate generally includes a polarizer and a protective plate for protecting the polarizer. The polarizer can be used, for example, by adsorbing and orienting iodine or dichroic dye to polyvinyl alcohol (PVA), and the protective plate is, for example, using triacetyl cellulose (TAC). Can be done.

  However, a polarizing plate including a polarizer and a protective plate not only has a complicated process and high production cost, but also increases the thickness of the polarizing plate, which affects the thickness of the display device.

  Therefore, a polarizing film that does not require a protective layer has been studied. The polarizing film does not include a separate protective plate, and is advantageous for realizing a thin display device.

  However, the polarizing film not only has low hardness and is easily scratched, but the dichroic dye in the polarizing film may move to other layers in contact with the polarizing film in an environment such as high temperature and high humidity. And optical properties can be degraded.

  One embodiment provides a polarizing film that can increase hardness, prevent migration of a dichroic dye, and prevent deterioration of optical properties.

  Another embodiment includes an antireflection film including the polarizing film.

  In another embodiment, a display device including the polarizing film or the antireflection film is provided.

According to one embodiment, a polarizing layer including a polymer resin and at least one dichroic dye having a maximum absorption wavelength (λ _max ) of 380 nm to 780 nm, and a cross-linked layer located on at least one surface of the polarizing layer. A polarizing film comprising a protective layer having a structure is provided.

  The crosslinked structure blocks the migration of the dichroic dye to the outside of the protective layer.

  The crosslinked structure is obtained by curing a photocurable monomer, a photocurable oligomer, a thermosetting resin, or a combination thereof.

  The photocurable monomer or the photocurable oligomer may be a urethane acrylate monomer, a urethane acrylate oligomer, an epoxy acrylate monomer, an epoxy acrylate oligomer, a polyether acrylate monomer, a polyether acrylate oligomer, a polyester acrylate monomer, a polyester acrylate oligomer, or a combination thereof. including.

  The crosslinked structure is obtained from a composition comprising about 5 to 60% by weight of the photocurable monomer or photocurable oligomer, about 0.01 to 5% by weight of a photoinitiator, and the remaining amount of solvent.

  The thermosetting resin includes a melamine resin, a urethane resin, an epoxy resin, or a combination thereof.

  The crosslinked structure is obtained from a composition comprising about 15 to 74% by weight of the thermosetting resin, about 0.1 to 10% by weight of a curing agent and the remaining amount of solvent.

  The polymer resin includes polyolefin, polyamide, polyester, polyacryl, polystyrene, a copolymer thereof, or a combination thereof.

  The polymer resin includes polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), polyethylene naphthalate (PEN), nylon, a copolymer thereof, or a combination thereof.

  When the polarizing film is allowed to stand at 80 ° C. for 500 hours, the light transmittance change rate (ΔT) is about 0.5% or less.

  When the polarizing film is left at 80 ° C. for 500 hours, the degree of polarization change (ΔPE) is 3% or less.

  When the polarizing film is left at 80 ° C. for 500 hours, the dichroic ratio change (ΔDR) is 0.5 or less.

  The protective layer has a thickness of about 10 μm or less.

  The protective layer has a thickness of about 0.1 μm to 5 μm.

  The polarizing layer is a molten mixture of the polymer resin and the dichroic dye.

  The dichroic dye is dispersed in the polymer resin, and the polymer resin is uniaxially stretched to about 400 to 1000%.

  According to another embodiment, an antireflection film including the polarizing film and a retardation film located on one surface of the polarizing film is provided.

  According to another embodiment, a display device including the polarizing film or the antireflection film is provided.

  By preventing the loss of the dichroic dye, it is possible to prevent the deterioration of the optical characteristics, and it is possible to increase the surface hardness and the thermal stability.

It is the schematic which showed the polarizing film which concerns on one implementation example. It is the schematic which showed the polarizing layer of the polarizing film of FIG. It is sectional drawing which showed schematically the antireflection film which concerns on one implementation example. It is the schematic which shows the external light antireflection principle of the antireflection film which concerns on one implementation example. It is sectional drawing which showed the liquid crystal display device which concerns on one implementation example. 1 is a cross-sectional view illustrating an organic light emitting display device according to an embodiment.

  Hereinafter, embodiments of the present invention will be described in detail so that a person having ordinary knowledge in the technical field to which the present invention belongs can easily carry out. However, the present invention can be embodied in various different forms and is not limited to the embodiments described herein.

  Hereinafter, a polarizing film according to an embodiment will be described with reference to FIGS. 1 and 2.

  FIG. 1 is a schematic diagram illustrating a polarizing film according to an embodiment, and FIG. 2 is a schematic diagram illustrating a polarizing layer of the polarizing film of FIG.

  Referring to FIG. 1, a polarizing film 50 according to an embodiment includes a polarizing layer 70 and protective layers 80a and 80b.

  First, the polarizing layer 70 will be described with reference to FIG.

  The polarizing layer 70 includes a polymer resin 71 and a dichroic dye 72 dispersed in the polymer resin 71.

  The polymer resin 71 can be selected from among hydrophobic polymer resins, and includes, for example, polyolefin, polyamide, polyester, polyacryl, polystyrene, copolymers thereof, or combinations thereof. The polymer resin 71 includes, for example, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyethylene terephthalate glycol (PETG), polyethylene naphthalate (PEN), nylon, copolymers thereof, or combinations thereof. Including, but not limited to.

  As an example, the polymer resin 71 is a mixture of at least two selected from polyethylene (PE), polypropylene (PP), and a copolymer of polyethylene and polypropylene (PE-PP). As an example, the polymer resin 71 is a mixture of polypropylene (PP) and polyethylene-polypropylene copolymer (PE-PP).

  The polypropylene (PP) has, for example, a melt flow index (MFI) of about 0.1 g / 10 min to about 5 g / 10 min. Here, the melt flow index (MFI) indicates the amount of molten polymer flowing per 10 minutes, and is related to the viscosity of the molten polymer. That is, it can be seen that the smaller the melt flow index (MFI), the higher the viscosity of the polymer, and the higher the melt flow index (MFI), the lower the viscosity of the polymer. When the melt flow index (MFI) of polypropylene is within the above range, the workability can be effectively improved, and the physical properties of the final product can be effectively improved. Specifically, polypropylene has a melt flow index (MFI) of about 0.5 g / 10 min to about 5 g / 10 min.

  The polyethylene-polypropylene copolymer (PE-PP) contains about 1% to about 50% by weight of ethylene groups based on the total content of the copolymer. When the content of ethylene groups in the polyethylene-polypropylene copolymer (PE-PP) is within the above range, the phase separation between polypropylene and polyethylene-polypropylene copolymer (PE-PP) is effectively prevented or alleviated. Can do. In addition, while having excellent light transmittance and orientation, it is possible to increase the stretch ratio when stretching, and to realize improved polarization characteristics. Specifically, the polyethylene-polypropylene copolymer (PE-PP) contains about 1% to about 25% by weight of ethylene groups based on the total content of the copolymer.

  The polyethylene-polypropylene copolymer (PE-PP) has a melt flow index (MFI) of about 5 g / 10 min to about 15 g / 10 min. When the melt flow index (MFI) of the polyethylene-polypropylene copolymer (PE-PP) is within the above range, the workability can be effectively improved, and the physical properties of the final product can be effectively improved. it can. Specifically, the polyethylene-polypropylene copolymer (PE-PP) has a melt flow index (MFI) of about 10 g / 10 min to about 15 g / 10 min.

  When the polymer resin 71 is a mixture of polypropylene (PP) and polyethylene-polypropylene copolymer (PE-PP), the polypropylene (PP) and the polyethylene-polypropylene copolymer (PE-PP) are about 1: 9 to about It is included in a 9: 1 weight ratio. When polypropylene (PP) and polyethylene-polypropylene copolymer (PE-PP) are included in the above range, it has excellent mechanical strength, but prevents crystallization of polypropylene and has an effect on haze characteristics. Can be improved. For example, polypropylene (PP) and polyethylene-polypropylene copolymer (PE-PP) are included in a weight ratio of about 4: 6 to about 6: 4, for example, in a weight ratio of about 5: 5.

  The polymer resin 71 may have a melt flow index (MFI) of about 1 g / 10 min to about 15 g / 10 min. When the melt flow index (MFI) of the polymer resin 71 is within the above range, excessive crystal is not formed in the resin, and excellent light transmittance can be secured, and at the same time, it can be produced into a film. It has a suitable viscosity and can improve processability. For example, the polymer resin 71 has a melt flow index (MFI) of about 5 g / 10 min to about 15 g / 10 min.

  The polymer resin 71 has a haze of about 5% or less. When the polymer resin 71 has a haze in the above range, the transmittance can be increased and excellent optical characteristics can be obtained. For example, the polymer resin 71 has a haze of about 2% or less, for example, a haze of about 0.5% to about 2%.

  The polymer resin 71 has a crystallinity of about 50% or less. When the polymer resin 71 has a crystallinity in the above range, haze can be lowered and excellent optical properties can be achieved. For example, the polymer resin 71 has a crystallinity of about 30% to about 50%.

  The dichroic dye 72 is dispersed in the polymer resin 71 and arranged in one direction along the extending direction of the polymer resin 71. The dichroic dye 72 has, for example, a rod shape that is long in one direction. The dichroic dye 72 can transmit only one polarization orthogonal component of the two polarization orthogonal components with respect to a predetermined wavelength region.

The dichroic dye 72 includes at least one having a maximum absorption wavelength (λ _max ) in the visible light region, and includes, for example, one or more types having a maximum absorption wavelength (λ _max ) at about 380 nm to 780 nm. .

  The decomposition temperature of the dichroic dye 72 is about 245 ° C. or higher. Here, the decomposition temperature refers to the temperature at which the weight of the dichroic dye 72 is reduced by 5% relative to the initial weight.

  The dichroic dye 72 is included in an amount of about 0.01 to 5 parts by weight with respect to 100 parts by weight of the polymer resin 71. By being included in the above range, sufficient polarization characteristics can be expressed without reducing the transmittance of the polarizing film. Within the above range, it is contained at about 0.05 to 1 part by weight with respect to 100 parts by weight of the polymer resin 71.

  The polarizing layer 70 is a melt-blend of the polymer resin 71 and the dichroic dye 72. The molten mixture is obtained by melting and mixing a polarizing layer composition containing the polymer resin 71 and the dichroic dye 72 at a temperature equal to or higher than the melting point (Tm) of the polymer resin 71.

  The composition for a polarizing layer includes the polymer resin 71 and the dichroic dye 72 described above, and each of the polymer resin 71 and the dichroic dye 72 is included in a solid form such as a powder. The composition for a polarizing layer has, for example, a solid content of about 90% by weight or more and does not need to contain a solvent, for example.

  The polarizing layer 70 is manufactured, for example, in a step of melt-mixing the composition for the polarizing layer, a step of manufacturing the sheet by pressing the molten mixture into a mold, and a step of uniaxially stretching the sheet.

  In the melt-mixing step, the composition for the polarizing layer is melt-mixed at, for example, about 300 ° C. or less, specifically about 50 to 300 ° C.

  The step of manufacturing the above-mentioned sheet is formed by putting the molten mixture into a mold and pressurizing with a high-pressure press, or by discharging to a chill roll through a T-die.

  In the uniaxial stretching step, stretching is performed at a temperature of about 30 to 200 ° C. and a stretch ratio of about 400% to about 1000%. Here, the stretching ratio refers to the ratio of the length before stretching of the sheet and the length after stretching, and means the extent that the sheet has been stretched after uniaxial stretching.

  In the melt-mixing step, the polarizing film composition is melt-mixed at, for example, about 300 ° C. or less, specifically about 50 to 300 ° C.

  The step of manufacturing the above-mentioned sheet is formed by putting the molten mixture into a mold and pressurizing with a high-pressure press, or by discharging to a chill roll through a T-die.

  In the uniaxial stretching step, stretching is performed at a temperature of about 30 to 200 ° C. and a stretch ratio of about 400% to about 1000%. Here, the stretching ratio refers to the ratio of the length before stretching of the sheet and the length after stretching, and means the extent that the sheet has been stretched after uniaxial stretching. The stretching direction may be the same as the length direction of the dichroic dye 72.

  The polarizing layer 70 has a relatively thin thickness of about 100 μm or less, for example, a thickness of about 30 μm to about 95 μm. By having the thickness within the above range, the thickness can be reduced as compared with a polarizing plate that requires a thick protective plate such as triacetyl cellulose (TAC), thereby realizing a thin display device. be able to.

  Hereinafter, the protective layers 80a and 80b will be described.

  The protective layers 80 a and 80 b are located on one or both surfaces of the polarizing layer 70 and protect the polarizing layer 70.

  The protective layers 80a and 80b have a crosslinked structure formed by intersecting a plurality of polymer chains extending in the first direction and a plurality of polymer chains extending in the second direction intersecting the first direction. The crosslinked structure forms, for example, a network or a network structure. The cross-linking structure can confine the dichroic dye 72 in the polarizing layer 70 by blocking or preventing the dichroic dye 72 of the polarizing layer 70 from migrating to the outside of the polarizing layer 70. Thereby, the loss of the dichroic dye 72 can be reduced and the physical properties of the polarizing film can be prevented from deteriorating.

  The loss of the dichroic dye 72 may occur particularly in the subsequent high-temperature process and / or standing at high temperature, but as an example, by reducing the loss of the dichroic dye 72 by the crosslinking structure as described above, When left standing for a time, the light transmittance change rate (ΔT) is about 0.5% or less, the polarization degree change rate (ΔPE) is about 3% or less, and the dichroic ratio change rate (ΔDR) is about 0.5%. Can be reduced to: Therefore, it is possible to prevent the optical characteristics of the polarizing film from being deteriorated by the subsequent high-temperature process and / or the high-temperature standing, thereby improving the reliability.

  The protective layers 80a and 80b are also positioned on one or both sides of the polarizing layer 70 to cover the surface of the polarizing layer 70, thereby preventing the surface of the polarizing layer 70 from being damaged. The hardness of the polarizing film can be increased.

  The protective layers 80a and 80b are positioned on one or both surfaces of the polarizing layer 70, and the polarizing layer 70 is relatively thin and fixed at a high distribution ratio. Shrinkage can be prevented, whereby the polarizing film can be prevented from being bent or deformed.

  The crosslinked structure can be formed by, for example, photocuring and / or thermosetting, for example, by curing a composition containing a photocurable monomer, a photocurable oligomer, a thermosetting resin, or a combination thereof. can get.

  The photocurable monomer or the photocurable oligomer is not particularly limited as long as it is a compound capable of forming a crosslinked structure by photocuring. For example, a urethane acrylate monomer, a urethane acrylate oligomer, an epoxy acrylate monomer, an epoxy acrylate oligomer, a poly It is selected from ether acrylate monomers, polyether acrylate oligomers, polyester acrylate monomers, polyester acrylate oligomers or combinations thereof.

  The composition includes, for example, about 5 to 60% by weight of a photocurable monomer or photocurable oligomer, about 0.01 to 5% by weight of a photoinitiator, and the remaining amount of solvent. The composition may further include, for example, one or more additives.

  A thermosetting resin will not be specifically limited if it is a compound which can form a crosslinked structure by thermosetting, For example, it selects from a melamine resin, a urethane resin, an epoxy resin, or these combination.

  The composition includes, for example, about 15 to 74% by weight of a thermosetting resin, about 0.1 to 10% by weight of a curing agent, and the remaining amount of solvent. The composition may further include, for example, one or more additives.

  The protective layers 80a and 80b have a thickness of about 10 μm or less, for example, and have a thickness of about 0.1 μm to 5 μm, for example. One of the protective layers 80a and 80b may be omitted in some cases.

  The protective layers 80a and 80b are formed by, for example, a vapor deposition process or a solution process.

  Hereinafter, the antireflection film including the polarizing film described above will be described.

  FIG. 3 is a cross-sectional view schematically illustrating an antireflection film according to an embodiment.

  The antireflection film 55 according to an embodiment includes the polarizing film 50, the retardation film 95 located on one surface of the polarizing film 50, and the adhesive layer 90 located between the polarizing film 50 and the retardation film 95. Including.

  As described above, the polarizing film 50 includes the polarizing layer 70 containing the polymer resin and the dichroic dye, and the protective layers 80a and 80b that are located on at least one surface of the polarizing layer 70 and have a crosslinked structure. The detailed contents are as described above, and the specific contents are omitted here.

  The retardation film 95 is, for example, a λ / 4 plate, and for example, linearly polarized light may be changed to circularly polarized light.

  The pressure-sensitive adhesive layer 90 includes, for example, a vacuum pressure-sensitive adhesive or an adhesive, and may be omitted in some cases.

  The antireflection film 55 is formed on one side or both sides of the display device, and particularly formed on the screen portion side of the display device to prevent reflection of light entering from the outside (hereinafter referred to as “external light”). be able to. Therefore, it is possible to prevent a decrease in visibility due to external light reflection.

  FIG. 4 is a schematic diagram illustrating an external light antireflection principle of an antireflection film according to an embodiment.

  Referring to FIG. 4, incident unpolarized light incident from the outside passes through the polarizing film 50 and only one polarization orthogonal component of the two polarization orthogonal components, that is, the first polarization orthogonal component. The light that is transmitted and polarized is converted into circularly polarized light while passing through a retardation film 95 such as a λ / 4 plate. While the circularly polarized light is reflected by the display panel 97 including the substrate and electrodes, the direction of circularly polarized light changes, and while the circularly polarized light passes through the retardation film 95 again, Only the other polarization orthogonal component, that is, the second polarization orthogonal component is transmitted. Since the second orthogonal polarization component cannot pass through the polarizing film 50 and light is not emitted to the outside, it has an effect of preventing reflection of external light.

  The polarizing film or the antireflection film is applied to various display devices.

  The display device is a liquid crystal display device.

  FIG. 5 is a cross-sectional view illustrating a liquid crystal display device according to an embodiment.

  Referring to FIG. 5, the liquid crystal display device includes a liquid crystal display panel 10 and a polarizing film 50 positioned on the lower and upper portions of the liquid crystal display panel 10.

  The liquid crystal display panel 10 includes a twisted nematic (TN) mode, a vertical alignment (PVA) mode, a planar alignment switching (IPS) mode, an OCB (optically compensated) mode, and the like.

  The liquid crystal display panel 10 includes a first display panel 100, a second display panel 200, and a liquid crystal layer 300 interposed between the first display panel 100 and the second display panel 200.

  The first display panel 100 includes, for example, a thin film transistor (not shown) formed on a substrate (not shown) and a first electric field generating electrode (not shown) connected thereto, The display panel 200 includes, for example, a color filter (not shown) and a second electric field generating electrode (not shown) formed on a substrate (not shown). However, the present invention is not limited to this, and a color filter may be included in the first display panel 100, and the first electric field generation electrode and the second electric field generation electrode may be located on the first display panel 100 together.

  The liquid crystal layer 300 includes a plurality of liquid crystal molecules. The liquid crystal molecules have positive or negative dielectric anisotropy. When the liquid crystal molecules have a positive dielectric anisotropy, the major axis is aligned substantially parallel to the surfaces of the first display panel 100 and the second display panel 200 in the absence of an electric field, and an electric field is applied. In this state, the major axis is oriented substantially perpendicular to the surfaces of the first display panel 100 and the second display panel 200. On the other hand, when the liquid crystal molecules have negative dielectric anisotropy, the major axis is almost perpendicular to the surfaces of the first display panel 100 and the second display panel 200 in the absence of an electric field. With the orientation applied and the electric field applied, the major axis is oriented substantially parallel to the surfaces of the first display panel 100 and the second display panel 200.

  The polarizing film 50 is located outside the liquid crystal display panel 10 and is shown in the drawing as being formed on the lower and upper parts of the liquid crystal display panel 10, respectively. And only one of the upper part and the upper part.

  As described above, the polarizing film 50 includes the polarizing layer 70 containing the polymer resin and the dichroic dye, and the protective layers 80a and 80b located on at least one surface of the polarizing layer 70. The detailed contents are as described above. is there.

  The display device is an organic light emitting display device.

  FIG. 6 is a cross-sectional view illustrating an organic light emitting display device according to an embodiment.

  Referring to FIG. 6, the organic light emitting display device according to an embodiment includes a base substrate 410, a lower electrode 420, an organic light emitting layer 430, an upper electrode 440, a sealing substrate 450, and an antireflection film 55.

  The base substrate 410 is made of glass or plastic.

  One of the lower electrode 420 and the upper electrode 440 is an anode, and the other is a cathode. The anode is an electrode into which holes are injected, and has a high work function and is made of a transparent conductive material from which emitted light is emitted to the outside, and is, for example, ITO or IZO. The cathode is an electrode into which electrons are injected, and is made of a conductive material that has a low work function and does not affect organic materials. For example, the cathode is selected from aluminum (Al), calcium (Ca), and barium (Ba). The

  The organic light emitting layer 430 includes an organic material that emits light when a voltage is applied to the lower electrode 420 and the upper electrode 440.

  An auxiliary layer (not shown) may be further included between the lower electrode 420 and the organic light emitting layer 430 and between the upper electrode 440 and the organic light emitting layer 430. The auxiliary layer includes a hole transporting layer, a hole injecting layer, an electron injecting layer, and an electron transporting layer for balancing electrons and holes. )including.

  The sealing substrate 450 is made of glass, metal, or polymer, and seals the lower electrode 420, the organic light emitting layer 430, and the upper electrode 440 to prevent moisture and / or oxygen from flowing in from the outside. .

  The antireflection film 55 includes the retardation film 95 and the polarizing film 50 as described above. The retardation film 95 can circularly polarize the light that has passed through the polarizing film 50 to generate a phase difference, and can affect the reflection and absorption of light. As described above, the polarizing film 50 includes the polarizing layer 70 containing the polymer resin and the dichroic dye, and the protective layers 80a and 80b located on at least one surface of the polarizing layer 70. The detailed contents are as described above. is there.

  The antireflection film 55 is disposed on the light exit side. For example, in the case of a bottom emission structure in which light is emitted to the base substrate 410 side, in the case of a front emission structure in which light is disposed on the outer side of the base substrate 410 and light is emitted to the sealing substrate 450 side. It is disposed outside the substrate 450.

  Hereinafter, embodiments of the present invention will be described in more detail through examples. However, the following examples are for illustrative purposes only and do not limit the scope of the present invention.

当該偏光フィルム用組成物を約２５０℃で、ＤＳＭ偏光層用組成物を約２３０℃で、ＤＳＭ社のＭｉｃｒｏ−ｃｏｍｐｏｕｎｄｅｒを使用して溶融混合する。次いで、当該溶融した混合物をシート状のモールドに入れた後、高温高圧プレスで加圧してフィルムを製造する。次いで、１１５℃で当該フィルムを１０００％倍率で一軸延伸（Ｉｎｓｔｒｏｎ社の引張試験器使用）して偏光層を製造する。 [Preparation of polarizing layer]
A polymer resin containing polypropylene (PP) and polypropylene-polyethylene copolymer (PP-PE) in 5: 5 (w / w), and the following chemical formulas 1, 2, 3 with respect to 100 parts by weight of the polymer resin: A composition for a polarizing film is prepared by mixing 0.5, 0.2, and 0.3 parts by weight of a dichroic dye represented by the formula:

The polarizing film composition is melt-mixed at about 250 ° C. and the DSM polarizing layer composition at about 230 ° C. using a DSM Micro-compounder. Next, the molten mixture is put into a sheet-like mold, and then pressed by a high-temperature and high-pressure press to produce a film. Next, the film is uniaxially stretched at a magnification of 1000% at 115 ° C. (using an Instron tensile tester) to produce a polarizing layer.

[Manufacture of polarizing film]
(Example 1)
After both surfaces of the polarizing layer prepared above are corona-treated (250 doses), a protective layer composition (CHSR33, manufactured by CC Tech Inc.) is applied to one surface of the polarizing layer using a doctor blade. Next, after the polarizing layer coated with the composition is dried at 85 ° C. for 5 minutes, it is cured by irradiation with a metal halide lamp (400 mJ / cm ² ) to form a protective layer having a thickness of about 5 μm. Next, a protective layer composition (CHSR33, manufactured by CC Tech Inc.) is applied to the other surface of the polarizing layer in the same manner, dried and cured, and a protective layer having a thickness of about 5 μm is formed to form a polarizing film. Manufacturing.

(Example 2)
A protective layer was formed on both surfaces of the polarizing layer in the same manner as in Example 1 except that CHSR35 (manufactured by CC Tech Inc.) was used instead of CHSR33 (manufactured by CC Tech Inc.) as the protective layer composition. Form a polarizing film.

(Comparative Example 1)
A polarizing film consisting only of a polarizing layer is produced without forming a protective layer.

表１を参考すると、実施例１、２による偏光フィルムは、比較例１による偏光フィルムと比べて表面硬度が高くなったことを確認することができる。 [Evaluation]
(Evaluation 1)
The surface hardness of the polarizing films according to Examples 1 and 2 and Comparative Example 1 is evaluated.
The surface hardness is evaluated by a pencil hardness measuring device (CORETECH, CT-PC1) method.
The results are shown in Table 1.

Referring to Table 1, it can be confirmed that the polarizing films according to Examples 1 and 2 have higher surface hardness than the polarizing film according to Comparative Example 1.

数式１において、
ＤＲは、二色比であり、

は、偏光フィルムの透過軸に平行に入射した光に対する偏光フィルムの光透過度であり、
Ｔ_⊥は、偏光フィルムの透過軸に垂直に入射した光に対する偏光フィルムの光透過度である。
偏光度は、下記の数式３によって求める。

数式３において、
ＰＥは、偏光度であり、

は、偏光フィルムの透過軸に平行に入射した光に対する偏光フィルムの光透過度であり、
Ｔ_⊥は、偏光フィルムの透過軸に垂直に入射した光に対する偏光フィルムの光透過度である。
その結果は、表２〜表４の通りである。

表２〜表４を参考すると、実施例１、２による偏光フィルムを適用した反射防止フィルムは、比較例１による偏光フィルムを適用した反射防止フィルムと比べて高温で長時間放置後、光透過度、偏光度および二色比の減少程度が非常に低いことが分かる。このことから、実施例１、２による偏光フィルムを適用した反射防止フィルムは、比較例１による偏光フィルムを適用した反射防止フィルムと比べて熱耐久性が非常に改善されたことを確認することができる。 (Evaluation 2)
Using a pressure-sensitive adhesive (PS-47, manufactured by Soken) on one surface of the polarizing films according to Examples 1 and 2 and Comparative Example 1, a retardation film (WRS, manufactured by Teijin) and a glass substrate were sequentially attached. An antireflection film is produced. The antireflection film is laminated in the order of a glass substrate, a reduced pressure adhesive, a retardation film, a reduced pressure adhesive, and a polarizing film.
After evaluating the light transmittance, polarization degree, and dichroic ratio (DR) of the antireflection film, the antireflection film is allowed to stand at 85 ° C. for 500 hours, and then the light transmittance, polarization degree, and dichroic color. Reassess the ratio.
The light transmittance is evaluated using a JASCO V-7100 UV / Vis spectrophotometer.
The measured light transmission is used to determine the dichroic ratio (DR) and the degree of polarization (PE).
The dichroic ratio (DR) is obtained by the following formula 1.

In Equation 1,
DR is the dichroic ratio,

Is the light transmittance of the polarizing film with respect to light incident parallel to the transmission axis of the polarizing film,
T _⊥ is the light transmittance of the polarizing film with respect to light incident perpendicular to the transmission axis of the polarizing film.
The degree of polarization is obtained by the following Equation 3.

In Equation 3,
PE is the degree of polarization,

Is the light transmittance of the polarizing film with respect to light incident parallel to the transmission axis of the polarizing film,
T _⊥ is the light transmittance of the polarizing film with respect to light incident perpendicular to the transmission axis of the polarizing film.
The results are as shown in Tables 2-4.

Referring to Tables 2 to 4, the antireflection film to which the polarizing films according to Examples 1 and 2 were applied was left for a long time at a higher temperature than the antireflection film to which the polarizing film according to Comparative Example 1 was applied. It can be seen that the degree of decrease in polarization degree and dichroic ratio is very low. From this, it is possible to confirm that the antireflection film to which the polarizing film according to Examples 1 and 2 is applied has a much improved thermal durability as compared with the antireflection film to which the polarizing film according to Comparative Example 1 is applied. it can.

表５を参考すると、実施例１、２による偏光フィルムは、比較例１による偏光フィルムと比べて熱収縮率が非常に低いことが分かる。 (Evaluation 3)
The thermal stability of the polarizing films according to Examples 1 and 2 and Comparative Example 1 is evaluated.
The thermal stability is evaluated by changing the length of the polarizing film after raising the temperature of the polarizing films according to Examples 1 and 2 and Comparative Example 1 to 85 ° C. at a rate of 10 ° C./min and leaving them at 85 ° C. for 5 hours. .
The results are shown in Table 5.

Referring to Table 5, it can be seen that the polarizing films according to Examples 1 and 2 have a very low thermal shrinkage rate as compared with the polarizing film according to Comparative Example 1.

  Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the attached drawings. Naturally, it is possible to implement and this is also within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Liquid crystal display panel 50 Polarizing film 70 Polarizing layer 71 Polymer resin 72 Dichroic dye 80a, 80b Protective layer 90 Adhesion layer 95 Phase difference film 100 1st display board 200 Liquid crystal layer 300 2nd display board 410 Base substrate 420 Lower electrode 430 Organic light emitting layer 440 Upper electrode 450 Sealing substrate

Claims (18)

A polarizing layer comprising a polymer resin and at least one dichroic dye having a maximum absorption wavelength at 380 nm to 780 nm;
A protective layer located on at least one surface of the polarizing layer and having a crosslinked structure;
A polarizing film comprising:   The polarizing film according to claim 1, wherein the crosslinked structure blocks movement of the dichroic dye to the outside.   The polarizing film according to claim 1, wherein the crosslinked structure is obtained by curing a photocurable monomer, a photocurable oligomer, a thermosetting resin, or a combination thereof.   The photocurable monomer or the photocurable oligomer may be a urethane acrylate monomer, a urethane acrylate oligomer, an epoxy acrylate monomer, an epoxy acrylate oligomer, a polyether acrylate monomer, a polyether acrylate oligomer, a polyester acrylate monomer, a polyester acrylate oligomer, or a combination thereof. The polarizing film according to claim 3.   The said crosslinked structure is obtained from the composition containing the said photocurable monomer or the said photocurable oligomer 5-60 weight%, 0.01-5 weight% of photoinitiators, and the residual amount solvent. Polarized film.   The polarizing film according to claim 3, wherein the thermosetting resin includes a melamine resin, a urethane resin, an epoxy resin, or a combination thereof.   The polarizing film according to claim 6, wherein the crosslinked structure is obtained from a composition containing 15 to 74% by weight of the thermosetting resin, 0.1 to 10% by weight of a curing agent, and the remaining amount of solvent.   The polarizing film according to claim 1, wherein the polymer resin includes polyolefin, polyamide, polyester, polyacryl, polystyrene, a copolymer thereof, or a combination thereof.   The polarizing film according to claim 8, wherein the polymer resin includes polyethylene, polypropylene, polyethylene terephthalate, polyethylene terephthalate glycol, polyethylene naphthalate, nylon, a copolymer thereof, or a combination thereof.   The polarizing film according to claim 1, wherein, when left at 80 ° C. for 500 hours, the rate of change in light transmittance is 0.5% or less.   The polarizing film according to claim 1, wherein the rate of change in polarization degree is 3% or less when left at 80 ° C. for 500 hours.   The polarizing film according to claim 1, wherein the dichroic ratio change is 0.5 or less when left at 80 ° C. for 500 hours.   The polarizing film according to claim 1, wherein the protective layer has a thickness of 10 μm or less.   The polarizing film according to claim 13, wherein the protective layer has a thickness of 0.1 μm to 5 μm.   The polarizing film according to claim 1, wherein the polarizing layer is a molten mixture of the polymer resin and the dichroic dye. The dichroic dye is dispersed in the polymer resin,
The polarizing film according to claim 1, wherein the polymer resin is uniaxially stretched to 400 to 1000%. The polarizing film according to any one of claims 1 to 16,
A retardation film located on one surface of the polarizing film;
Antireflection film containing   A display device comprising the polarizing film according to claim 1 or the antireflection film according to claim 17.

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